1. The problem statement, all variables and given/known data A car is travelling at 30m/s around a bend of radius 70m. What coefficient of static friction between the tires and the road is required to ensure the car will not slip? 2. Relevant equations 3. The attempt at a solution I know that the centripetal acceleration is a=30^2/70 and I know that this acceleration has to be canceled out by the frictional force for the car to not slip, but I am not sure out to calculate frictional force F=mA without a mass for the car.